﻿using System;
using System.Drawing;
using System.Web.UI.WebControls;
using System.Drawing;
namespace MatchIns.Common
{
    public class Upload
    {
        /// <summary>
        /// 上传文件是否为图片
        /// </summary>
        /// <param name="file"></param>
        /// <returns></returns>
        public static bool IsImage(FileUpload file)
        {
            string allowUploadFile = "image/fax,image/gif,image/x-icon,image/jpeg,application/x-jpg,image/png,image/tiff";
            return !(allowUploadFile.IndexOf(file.PostedFile.ContentType) == -1);
        }

        /// <summary>
        /// 上传文件是否为图片
        /// </summary>
        /// <param name="file"></param>
        /// <returns></returns>
        public static bool IsImage(System.Web.HttpPostedFile file)
        {
            string allowUploadFile = "image/fax,image/gif,image/x-icon,image/jpeg,application/x-jpg,image/png,image/tiff";
            return !(allowUploadFile.IndexOf(file.ContentType) == -1);
        }
        public static string UploadImage(FileUpload file,string fileSavePath,int thumbWidth)
        {
            string fileName = DateTime.Now.ToString("yyyyMMddHHmmssff") + System.IO.Path.GetExtension(file.FileName);
            string fileSaveDirectory = fileSavePath + fileName;
            string thumbSaveDirectory = 
                fileSaveDirectory.EndsWith("/") ? fileSavePath + "thumb/" + fileName : fileSavePath + "/thumb/" + fileName;

            //上传文件大小
            if (file.PostedFile.ContentLength > 2 * 1024 * 1024)
            {
                throw new Exception("上传文件最大为2MB");
                //errors.Items.Add("上传文件最大为2MB");
            }
            else if (!IsImage(file))//上传文件是否为图片             
            {
                throw new Exception("上传文件不是图片类型");
            }
            else
            {

                //保存原图
                file.SaveAs(System.Web.HttpContext.Current.Server.MapPath(fileSaveDirectory));
                //保存缩略图
                ThumbImage.MakeThumbnail(System.Web.HttpContext.Current.Server.MapPath(fileSaveDirectory),
                    System.Web.HttpContext.Current.Server.MapPath(thumbSaveDirectory), 
                    thumbWidth, 
                    0, 
                    "W");
            }

            return fileName;
        }

        public static string UploadImage(System.Web.HttpPostedFile file, string fileSavePath, int thumbWidth)
        {
            string fileName = DateTime.Now.ToString("yyyyMMddHHmmssff") + System.IO.Path.GetExtension(file.FileName);
            string fileSaveDirectory = fileSavePath + fileName;
            string thumbSaveDirectory =
                fileSaveDirectory.EndsWith("/") ? fileSavePath + "thumb/" + fileName : fileSavePath + "/thumb/" + fileName;

            //上传文件大小
            if (file.ContentLength > 2 * 1024 * 1024)
            {
                throw new Exception("上传文件最大为2MB");
                //errors.Items.Add("上传文件最大为2MB");
            }
            else if (!IsImage(file))//上传文件是否为图片             
            {
                throw new Exception("上传文件不是图片类型");
            }
            else
            {

                //保存原图
                file.SaveAs(System.Web.HttpContext.Current.Server.MapPath(fileSaveDirectory));
                //保存缩略图
                ThumbImage.MakeThumbnail(System.Web.HttpContext.Current.Server.MapPath(fileSaveDirectory),
                    System.Web.HttpContext.Current.Server.MapPath(thumbSaveDirectory),
                    thumbWidth,
                    0,
                    "W");
            }

            return fileName;
        }
    }

    /// <summary>
    ///生产缩略图
    /// </summary>
    public class ThumbImage
    {
        public ThumbImage()
        {
            //
            //TODO: 在此处添加构造函数逻辑
            //
        }
        /// <summary>
        /// 生成缩略图
        /// </summary>
        /// <param name="originalImagePath">源图路径（物理路径）</param>
        /// <param name="thumbnailPath">缩略图路径（物理路径）</param>
        /// <param name="width">缩略图宽度</param>
        /// <param name="height">缩略图高度</param>
        /// <param name="mode">生成缩略图的方式</param>    
        public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)
        {
            System.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath);

            int towidth = width;
            int toheight = height;

            int x = 0;
            int y = 0;
            int ow = originalImage.Width;
            int oh = originalImage.Height;

            switch (mode)
            {
                case "HW"://指定高宽缩放（可能变形）                
                    break;
                case "W"://指定宽，高按比例                    
                    toheight = originalImage.Height * width / originalImage.Width;
                    break;
                case "H"://指定高，宽按比例
                    towidth = originalImage.Width * height / originalImage.Height;
                    break;
                case "Cut"://指定高宽裁减（不变形）                
                    if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
                    {
                        oh = originalImage.Height;
                        ow = originalImage.Height * towidth / toheight;
                        y = 0;
                        x = (originalImage.Width - ow) / 2;
                    }
                    else
                    {
                        ow = originalImage.Width;
                        oh = originalImage.Width * height / towidth;
                        x = 0;
                        y = (originalImage.Height - oh) / 2;
                    }
                    break;
                default:
                    break;
            }

            //新建一个bmp图片
            System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight);

            //新建一个画板
            Graphics g = System.Drawing.Graphics.FromImage(bitmap);

            //设置高质量插值法
            g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

            //设置高质量,低速度呈现平滑程度
            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

            //清空画布并以透明背景色填充
            g.Clear(Color.Transparent);

            //在指定位置并且按指定大小绘制原图片的指定部分
            g.DrawImage(originalImage, new Rectangle(0, 0, towidth, toheight),
                new Rectangle(x, y, ow, oh),
                GraphicsUnit.Pixel);

            try
            {
                //以jpg格式保存缩略图
                bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
            }
            catch (System.Exception e)
            {
                throw e;
            }
            finally
            {
                originalImage.Dispose();
                bitmap.Dispose();
                g.Dispose();
            }
        }
    }
}